The effect of radiation therapy (RT) on the absolute numbers and functions of lymphocyte populations from patients with a variety of cancers (primarily carcinoma of the breast, cervix, lung and ovary) will be examined. Mononuclear cells isolated from the peripheral blood before, during and after RT, will be characterized as T cells, B cells or monocytes. The numbers of T cells, B cells and monocytes will be enumerated by rosette tests (E-rosettes for T cells, and EA or EAC rosettes for B cells and monocytes), fluorescent staining of populations of T and B cells with specific antisera and specific cytochemical stains for monocytes. The functions of mononuclear cells to be examined include 1) blastogenesis measured by incorporation of radiolabelled nucleosides (uridine and thymidine) into cells stimulated in vitro with mitogens (PHA, PWM or ConA); 2) production of the lymphokin, lymphotoxin in response to in vitro stimulation with the above mitogens; 3) the ability of the mononuclear cells to participate in mixed lymphocyte culture reactions and; 4) to respond in PHA-dependent cell cytotoxicity reactions. We will also study the effect of various antisera on the above functional tests. We will attempt to correlate specific cell populations, and/or the functional capacities of specific cell populations after RT with prognosis. We hope to be able to follow the patients for up to 5 years after their treatment. BIBLIOGRAPHIC REFERENCES: Stratton, J.A., Byfield, P.E., Byfield, J.E., Small, R.C., Benfield, J., and Pilch, Y., 1975, A comparison of the acute effects of radiation therapy, including or excluding the thymus, on the lymphocyte subpopulations of cancer patients. J. Clin. Invest. 56:88-97. Byfield, P.E., and Stratton, J.A., 1976, The effect of radiation therapy on lymphocyte subpopulations of cancer patients. UCLA Cancer Bull 3 (2).